US4639796A - Arrangement for positioning a transducer to at least one track of a tape-shaped recording medium - Google Patents

Arrangement for positioning a transducer to at least one track of a tape-shaped recording medium Download PDF

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Publication number
US4639796A
US4639796A US06/687,527 US68752784A US4639796A US 4639796 A US4639796 A US 4639796A US 68752784 A US68752784 A US 68752784A US 4639796 A US4639796 A US 4639796A
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United States
Prior art keywords
recording medium
transducer
edge
arrangement
positioning
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US06/687,527
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English (en)
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Erik Solhjell
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Tandberg Data Storage AS
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Tandberg Data AS
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Assigned to TANDBERG DATA A/S. A NORWEGIAN CORP. reassignment TANDBERG DATA A/S. A NORWEGIAN CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SOLHJELL, ERIK
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Assigned to TANDBERG DATA STORAGE AS reassignment TANDBERG DATA STORAGE AS ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TANDBERG DATA A/S
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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B21/00—Head arrangements not specific to the method of recording or reproducing
    • G11B21/02—Driving or moving of heads
    • G11B21/08—Track changing or selecting during transducing operation
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
    • G11B5/55—Track change, selection or acquisition by displacement of the head
    • G11B5/5504—Track change, selection or acquisition by displacement of the head across tape tracks
    • G11B5/5508—Control circuits therefor

Definitions

  • the present invention relates to an arrangement for positioning a transducer with respect to at least one track of a tape-shaped recording medium, whereby the transducer is displaceable perpendicular to the moving direction of the recording medium using a positioning device and an opto-electronic sensor comprises a light barrier device and a converter such that an active light beam of the light barrier is partially interrupted by an edge of the recording medium and the converter produces a control signal assigned to the interruption of the light beam to the positioning device.
  • a magnetic head which contains one or more write and/or read heads is also provided as the transducer and a magnetic tape is generally provided as the tape-shaped recording medium.
  • Such an arrangement can also be employed in an optical memory in which data are recorded on a suitable, tape-shaped recording medium, for example, using a laser.
  • a tape-shaped recording medium for example a magnetic tape
  • a tape-shaped recording medium is usually guided between stationary guide rollers at both sides of the magnetic head in order to hold the magnetic tape in a stable position.
  • a disruption or deviation of the magnetic tape relative to the magnetic head and perpendicular to the direction of movement of the tape often occurs as a consequence of tolerances in the manufacture of the guide rollers, as a consequence of play between the magnetic tape and the guide rollers, and as a consequence play in the seating of the guide rollers.
  • this deviation of the magnetic tape can have a disruptive influence since, on the one hand, the individual write and read heads are no longer accurately positioned to the corresponding track and since, on the other hand, the number of parallel tracks and, therefore, the storage capacity of the magnetic tape becomes restrictive.
  • the Japanese Patent No. 55-13 25 discloses an arrangement in which opto-electronic sensing arrangements, designed as light barriers, are provided in the proximity of the edges of the magnetic tape for the purpose of active positioning to the tracks of the magnetic tape.
  • the light transmitted from a light transmitter to a light receiver is respectively partially interrupted by the magnetic tape.
  • Dependent upon the magnitude of the interruption and, therefore, dependent upon the vertical motion of the magnetic tape a device which varies the tension of the magnetic tape and thus compensates movements of the magnetic tape in the vertical direction is driven.
  • This known arrangement is likewise not suitable when the magnetic head is designed so as to be displaceable to various tracks of the magnetic tape by the positioning device. Further, this known arrangement requires a relatively high expense since the apparatus for varying the pre-tension of the magnetic tape must be additionally provided.
  • a further arrangement for positioning a magnetic head to the tracks of the magnetic tape is known from the British published application No. 2,008,290, fully incorporated herein by this reference.
  • This known arrangement likewise comprises two opto-electronic sensing devices disposed at the magnetic head which sense the edges of the magnetic tape. The signals output by the light receivers of the sensing arrangements are subtracted from one another and are supplied to a positioning device which respectively displaces the magnetic head in the vertical direction until the difference between the signals disappears.
  • This known arrangement can likewise not be employed when the magnetic head is positionable to different tracks of the magnetic tape. In this case, the control signal is constant and can no longer be employed as a controlled variable for accurate positioning.
  • the object is achieved, according to one embodiment of the present invention, by providing that the light barrier device is arranged fixed and the converter generates a control signal from the signal output by the light barrier and emits the control signal to the positioning device.
  • the position of the transducer in the transverse direction of the recording medium is controlled with the positioning device such that the transducer follows the edges of the recording medium in terms of its position and transverse direction.
  • the light transmitter and/or a light receiver of the light barrier is mechanically connected to a transducer which is positionable to various tracks of the recording medium using a positioning device.
  • the active light beam of the light barrier has an expanse in the region of the edge of the recording medium which is at least equal to the maximum stroke of the transducer upon positioning to the various tracks.
  • the converter generates control signals whose momentary value is assigned to the respective displacement of the transducer relative to the edge of the recording medium.
  • the arrangement of the invention has the advantage that it requires a particularly low expense, since a positioning device provided for positioning the transducer to various tracks of the recording medium is also employed for the accurate positioning of the transducer to a track.
  • a particularly low expense is further achieved in that only a single sensing arrangement is required.
  • a further sensing arrangement can be provided at the other edge of the recording medium.
  • the control signal can likewise be generated by way of subtraction of the signals output by the two sensing arrangements.
  • a further control signal is generated by subtraction of a constant value from the control signal and this further control signal is supplied to the positioning device.
  • control signals can occur using analog or digital circuits.
  • the corresponding converter contains only an amplifier which can be designed as a summing amplifier or a differential amplifier, depending upon whether one or two sensing elements are provided, or whether a respective constant value is subtracted from the original control signal in order to generate the further control signal.
  • the amplifier is followed by an analog/digital converter which, in turn, is followed by a digital control unit, for example a microcomputer, which respectively outputs a numerical value to the positioning device in order to accurately position the magnetic head.
  • a constant numerical value or a numerical value dependent upon the track to which the transducer is being positioned can also be subtracted from this value.
  • a magnetic head comprising one or more write and/or read heads is advantageously provided as the transducer.
  • the sensing arrangement can also be employed for recognizing the edge of the recording medium. This, for example, is possible when the sensing device, together with the transducer, can be displaced to such a degree that the light beam between the light transmitter and the light receiver of the sensing arrangement is no longer interrupted by the recording medium.
  • FIG. 1 is a block diagram of a first exemplary embodiment of the invention
  • FIG. 2 is a block diagram of a first embodiment of a sensing arrangement
  • FIG. 3 is a block diagram of a second embodiment of the sensing arrangement
  • FIG. 4 is a block diagram of a portion of the sensing arrangement.
  • FIG. 5 is a block diagram of a second embodiment of the invention.
  • a tape-shaped recording medium for example a magnetic tape
  • a transducer 4 for example a magnetic head
  • the transducer 4 can contain one or more write and/or read heads.
  • the positioning device 5 can be designed so that it can position the write and/or read heads of the transducer 4 to those tracks of the recording medium 1 and/or such that it can execute a fine positioning to at least one track.
  • Such positioning devices are generally known in the art and are disclosed, for example, in the European published application No. 32 660, in the British published application No. 2,008,290, in U.S. Pat. No. 3,524,196 and in the German published application No. 31 12 886, all of which are fully incorporated herein by this reference.
  • the arrangement contains a sensing device 8 formed of a light barrier 6 and a converter 7, the sensing device 8 emitting a control signal S1 to the positioning device 5 whose momentary value is assigned to the transverse movement of the recording medium 1 and which effects a corresponding displacement of the transducer 4 by the positioning device 5.
  • the position of the transducer 4 relative to the recording medium 1 is controlled by the control signal Sl such that the position of the transducer 4 in the transverse direction of the recording medium respectively follows the edge thereof. It therefore becomes possible to increase the number of tracks on the recording medium 1.
  • a control unit 9 supplies the positioning device 5 with a positioning signal S2 which effects the setting to the respective track by the positioning device 5.
  • a fine positioning of the transducer 4 to the corresponding track or, respectively, tracks also occurs in this case using the control signal S1.
  • the light barrier 6 can be designed as a hole light barrier or as a reflective light barrier. It can be operated upon the use of visible or invisible light. Further, a further light barrier 10 can be provided at the other edge of the recording medium 1, this further light barrier 10 being likewise connected to the converter 7 and the control signal S1 being generated from the difference of the respective coverage by the recording medium 1.
  • the embodiment of a light barrier 6 illustrated in FIG. 2 is designed as a hole light barrier.
  • the light transmitter which is designed, for example, as a light-emitting diode, transmits modulated or unmodulated light to a light receiver 12.
  • the light beam is partially masked by the recording medium 1.
  • the light transmitter 11 and the light receiver 12 are arranged such that the recording medium 1 masks half the light beam in the normal case. Given a transverse movement of the recording medium 1, the light beam is correspondingly masked more or less, so that the corresponding control signal S1 can be generated.
  • FIG. 3 A further illustrative embodiment of the light barrier 6 is illustrated in FIG. 3 and is likewise designed as a hole light barrier, whereby a mirror 13 is disposed between the light transmitter 11 and the light receiver 12.
  • both the light transmitter and the light receiver are disposed at the side of the recording medium and a mirror is provided at the other side of the recording medium, in this case, for example, a mirror disposed parallel to the recording medium 1.
  • the light barrier is fixed and the active diameter of the light beam is greater than the possible movement of the recording medium 1 in the transverse direction.
  • the converter 7 is designed as an amplifier which amplifies a signal S0 emitted by the light barrier 6 and assigned to the transverse movement of the recording medium and supplied the same to the positioning device 5 as a control signal S1.
  • the amplifier can also be designed such that a respective constant value, assigned to the partial masking of the light beam in the normal case, is subtracted from the momentary value of the signal S0 or the signal S1.
  • a converter 7 shown in FIG. 4 operates in a digital manner.
  • This converter 7 also contains an amplifier 14 to which the signal S0 is supplied from the light receiver 12 of the light barrier.
  • the amplifier is followed by a analog-to-digital converter 15 which assigns a digital numerical value to the respective momentary value of the signal at the output of the amplifier 14 and supplies the numerical value to a digital circuit for the determination of a digital control signal S1.
  • the digital circuit is advantageously designed as a microcomputer 16.
  • the microcomputer is supplied with a constant value by way of a signal S3, the constant value being respectively subtracted from the value output by the analog-to-digital converter 15 in order to supply the positioning device 5 with a control signal S1 assigned to the deviation of the position of the recording medium 1 from its reference position in the transverse direction.
  • the control signal S2 is additionally supplied to the positioning device 5 by the control unit 9.
  • the light barrier 6 is not stationary, but is at least partially mechanically connected to the transducer 4 which is displaceable in the transverse direction of the recording medium.
  • the positioning device 5 is thereby designed such that the transducer is positionable to various tracks on the recording medium 1.
  • the active expanse of the light beam of the light barrier 6 in the transverse direction of the recording medium 1 is thereby at least as large as the maximum possible stroke in positioning the transducer 4.
  • the arrangement of the light barrier 6 can occur in such a manner that either the light transmitter 11 or the light receiver 12 or both the light transmitter 11 and the light receiver 12 are mechanically connected to the transducer 4, as is disclosed in a similar manner in the British published application No. 2,008,290.
  • the control unit 9 emits the control signal S2 to the positioning device 5 in order to position the transducer 4 to the corresponding track or the corresponding tracks on the recording medium 1.
  • the converter 7 is designed in a manner similar to the converter illustrated in FIG. 4; however, it is not a constant value, but a value dependent on the respective track that is subtracted from the signal S0 output by the light barrier 6 in order to generate the control signal S1 in order to therefore produce a corresponding differential signal which indicates the deviation of the actual position from the reference position.
  • the distance between the position of the transducer 4 and the edge of the recording medium 1 is maintained constant, regardless of the play of the recording medium in the guide rollers 2 and 3, so that the reliability when recording and playing back data is increased and so that the track density, i.e. the number of parallel tracks on the recording medium, can be increased.
  • the converter 7 is constructed only of analog components, only of analog components, only the amplifier 14 is employed, this being designed as a differential amplifier and an analog value corresponding to the signal S3 is subtracted at its inverting input.
  • the transducer 4 be displaceable using the positioning device 5 perpendicular to the moving direction of the recording medium so that a degree that the torsion of the light barrier 6 disposed on the transducer 4 is no longer masked by the recording medium 1.
  • the momentary value of the signal S0 and of the control signal S1 is modified so that the edge of the recording medium 1 is recognized.
  • the analogous case applies when the transducer 4 is displaced in the upper direction to such a degree that the light beam of the light barrier 6 is completely masked by the recording medium.
  • the edge of the recording medium is again recognized on the basis of the change in the momentary value of the signal S0 or of the control signal S1.
  • the control unit 9 can output corresponding control signals to the positioning device 5 in order to accurately position the transducer 4 to one or more tracks of the recording medium. Dynamic changes of the position of the recording medium 1 in the transverse direction are then continuously compensated using the converter 7.

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  • Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
US06/687,527 1983-12-30 1984-12-28 Arrangement for positioning a transducer to at least one track of a tape-shaped recording medium Expired - Lifetime US4639796A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3347632 1983-12-30
DE19833347632 DE3347632A1 (de) 1983-12-30 1983-12-30 Anordnung zum positionieren eines wandlers auf mindestens einer spur eines bandfoermigen aufzeichnungstraegers

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US4639796A true US4639796A (en) 1987-01-27

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DE (1) DE3347632A1 (enrdf_load_stackoverflow)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5050017A (en) * 1989-08-23 1991-09-17 Eastman Kodak Company Memory guided magnetic tape tracking
US5196969A (en) * 1989-03-31 1993-03-23 Sharp Kabushiki Kaisha Head positioning system for serpentine magnetic recording/reproducing system
US5262908A (en) * 1990-02-20 1993-11-16 Sharp Kabushiki Kaisha Tracking control device for magnetic recording/reproducing apparatus
US5270529A (en) * 1991-05-24 1993-12-14 Victor Company Of Japan, Ltd. Device for sensing rotary head position of magnetic recording and reproducing apparatus
US5285331A (en) * 1989-02-23 1994-02-08 Wangtek Incorporated System for aligning a read head gap over a track of magnetic data
US5294791A (en) * 1991-12-30 1994-03-15 Tandberg Data A/S System and a method for controlling position of a magnetic head relative to a servo track of a tape by optical detection of an edge of the tape
WO1994006119A1 (en) * 1992-09-09 1994-03-17 Archive Corporation Magnetic head guidance and calibration system and method description
US5379165A (en) * 1993-03-19 1995-01-03 Tandberg Data A/S Method and apparatus for improving the accuracy of a tape servo track seek algorithm by using longitudinally correlated waveforms of lateral tape movement unique to each tape cassette
US5394277A (en) * 1992-05-13 1995-02-28 Tandberg Data A/S Method for determining servo track pair position and longitudinal tape position for a tape using dedicated servo format
US5400200A (en) * 1992-09-14 1995-03-21 Eastman Kodak Company Magnetic head suspension apparatus
US5432652A (en) * 1993-06-14 1995-07-11 International Business Machines Corporation Servo and data format for magnetic tape having plural spaced-apart servo areas interleaved with data track areas having serpentine track scanning using any one of a plurality of number of concurrently accessed tracks
US5457586A (en) * 1990-08-14 1995-10-10 Tandberg Data A/S Method and arrangement for positioning a magnetic head relative to the storage medium of a magnetic layer storage
US5574602A (en) * 1993-06-14 1996-11-12 International Business Machines Corporation Processing servo signals concurrently read from plural spaced-apart servo areas for a magnetic tape having serpentine data track scanning
US5872675A (en) * 1997-01-21 1999-02-16 Tandberg Data Asa Tape cartridge with integrated mirror tracking mechanism
US5886845A (en) * 1996-08-13 1999-03-23 Imation Corp. Tape pack shift detection and retensioning methods and drive apparatus regarding same
US20020186497A1 (en) * 2001-06-07 2002-12-12 Fuji Photo Film Co., Ltd. Servo signal recording device and servo signal verifying device
US20060098331A1 (en) * 2004-11-10 2006-05-11 Certance Llc, A Delaware Limited Liability Company System and method for measuring the position of a tape drive head
US20060098328A1 (en) * 2004-11-10 2006-05-11 Certance Llc, A Delaware Limited Liability Company System and method for tape drive control
US20060187569A1 (en) * 2005-02-18 2006-08-24 Fuji Photo Film Co., Ltd. Servo track verification apparatus and servo writer

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3622532C2 (de) * 1986-07-04 1994-08-11 Blaupunkt Werke Gmbh Verfahren und Anordnung zur Wiedergabe von digitalen Daten
US5229620A (en) * 1991-12-31 1993-07-20 Tandberg Data A/S System for integrated tape hole detection by detecting an edge of the tape and/or a pattern on the tape
JP2006227982A (ja) 2005-02-18 2006-08-31 Pfu Ltd Ｍｉｃｒ読取機構

Citations (1)

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US4176381A (en) * 1977-11-11 1979-11-27 U.S. Philips Corporation Recording and/or reproducing apparatus for a magnetic record carrier in the form of a tape, provided with a control system for the magnetic head position

Family Cites Families (2)

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JPS55132522A (en) * 1979-04-02 1980-10-15 Olympus Optical Co Ltd Automatic tracking method for magnetic tape
JPS56101622A (en) * 1980-01-18 1981-08-14 Olympus Optical Co Ltd Autotracking system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4176381A (en) * 1977-11-11 1979-11-27 U.S. Philips Corporation Recording and/or reproducing apparatus for a magnetic record carrier in the form of a tape, provided with a control system for the magnetic head position

Cited By (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5285331A (en) * 1989-02-23 1994-02-08 Wangtek Incorporated System for aligning a read head gap over a track of magnetic data
US5196969A (en) * 1989-03-31 1993-03-23 Sharp Kabushiki Kaisha Head positioning system for serpentine magnetic recording/reproducing system
US5050017A (en) * 1989-08-23 1991-09-17 Eastman Kodak Company Memory guided magnetic tape tracking
US5262908A (en) * 1990-02-20 1993-11-16 Sharp Kabushiki Kaisha Tracking control device for magnetic recording/reproducing apparatus
US5457586A (en) * 1990-08-14 1995-10-10 Tandberg Data A/S Method and arrangement for positioning a magnetic head relative to the storage medium of a magnetic layer storage
US5270529A (en) * 1991-05-24 1993-12-14 Victor Company Of Japan, Ltd. Device for sensing rotary head position of magnetic recording and reproducing apparatus
US5294803A (en) * 1991-12-30 1994-03-15 Tandberg Data A/S System and a method for optically detecting an edge of a tape
US5294791A (en) * 1991-12-30 1994-03-15 Tandberg Data A/S System and a method for controlling position of a magnetic head relative to a servo track of a tape by optical detection of an edge of the tape
US5394277A (en) * 1992-05-13 1995-02-28 Tandberg Data A/S Method for determining servo track pair position and longitudinal tape position for a tape using dedicated servo format
JP3362851B2 (ja) 1992-09-09 2003-01-07 シーゲイト リムーヴァブル ストーレッジ ソリューションズ リミテッド ライアビリティ カンパニー 磁気ヘッド案内／校正装置および方法
US5491595A (en) * 1992-09-09 1996-02-13 Conner Peripherals, Inc. Magnetic head guidance and calibration system and method description
WO1994006119A1 (en) * 1992-09-09 1994-03-17 Archive Corporation Magnetic head guidance and calibration system and method description
US5400200A (en) * 1992-09-14 1995-03-21 Eastman Kodak Company Magnetic head suspension apparatus
US5379165A (en) * 1993-03-19 1995-01-03 Tandberg Data A/S Method and apparatus for improving the accuracy of a tape servo track seek algorithm by using longitudinally correlated waveforms of lateral tape movement unique to each tape cassette
US5432652A (en) * 1993-06-14 1995-07-11 International Business Machines Corporation Servo and data format for magnetic tape having plural spaced-apart servo areas interleaved with data track areas having serpentine track scanning using any one of a plurality of number of concurrently accessed tracks
US5574602A (en) * 1993-06-14 1996-11-12 International Business Machines Corporation Processing servo signals concurrently read from plural spaced-apart servo areas for a magnetic tape having serpentine data track scanning
US5886845A (en) * 1996-08-13 1999-03-23 Imation Corp. Tape pack shift detection and retensioning methods and drive apparatus regarding same
US5872675A (en) * 1997-01-21 1999-02-16 Tandberg Data Asa Tape cartridge with integrated mirror tracking mechanism
US20020186497A1 (en) * 2001-06-07 2002-12-12 Fuji Photo Film Co., Ltd. Servo signal recording device and servo signal verifying device
US6865050B2 (en) * 2001-06-07 2005-03-08 Fuji Photo Film Co., Ltd. Servo signal recording device and servo signal verifying device using edge detection
US20060098331A1 (en) * 2004-11-10 2006-05-11 Certance Llc, A Delaware Limited Liability Company System and method for measuring the position of a tape drive head
US20060098328A1 (en) * 2004-11-10 2006-05-11 Certance Llc, A Delaware Limited Liability Company System and method for tape drive control
EP1657711A1 (en) * 2004-11-10 2006-05-17 Certance LLC System and method for tape drive control
US7203027B2 (en) 2004-11-10 2007-04-10 Certance, Llc System and method for measuring the position of a tape drive head
US7230788B2 (en) 2004-11-10 2007-06-12 Certance, Llc System and method for tape drive control
US20060187569A1 (en) * 2005-02-18 2006-08-24 Fuji Photo Film Co., Ltd. Servo track verification apparatus and servo writer
US7206161B2 (en) * 2005-02-18 2007-04-17 Fujifilm Corporation Servo track verification apparatus and servo writer

Also Published As

Publication number Publication date
DE3347632C2 (enrdf_load_stackoverflow) 1988-08-04
DE3347632A1 (de) 1985-07-11

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